Relationships and Classification of Primitive Hexapods and Insects

该项目将利用分子序列和形态学数据的结合，研究四种基本六足动物类群——舌颌目（Entognatha）、Thysanura、古翅目（Paleoptera）和翅目（Plecoptera）的系统发育关系。在这四个谱系的起源中，我们发现了泥盆纪以来决定昆虫多样性的基本事件。阐明这些组之间的关系将允许更精确地解释它们的属性。此外，现有分类群的健全的枝状图将有助于我们理解有问题的化石分类群。将确定核18S rDNA区域的DNA序列。这些数据将直接与形态学特征矩阵相结合。在较低层次的系统关系基础上，为每个较高的类群选择具有代表性的分类群。根据前期研究的结论，选取距离较远的类群，推断六足目、昆虫目、双足目和新翅目的地平面。将使用酒精保存和干燥的博物馆标本，以确保包括最基本的谱系，从而产生更可靠的数据集。这种方法结合了多个基因座、基于系统发育的采样和广泛的形态分析，确保了这项工作将增加我们对这些最古老的六足动物谱系的进化和系统学的理解。

This project will examine the phylogenetic relationships of four basal hexapod groups--Entognatha, Thysanura, Paleoptera and Plecoptera--using a combination of molecular sequence and morphological data. In the origin of these four lineages, we find the fundamental events that define insect diversity since the Devonian. Illuminating the relationships among these groups will allow a more precise interpretation of their attributes. Moreover, robust cladograms of extant taxa will aid in our understanding of problematic fossil taxa. DNA sequences will be determined for the nuclear 18S rDNA regions. These data will be combined directly with a matrix of morphological features. Representative taxa will be chosen for each of the higher groups based on the systematic relationships at lower hierarchical levels. Using the conclusions of earlier studies, cladistically distant taxa will be chosen to infer the ground plans of Hexapoda, Insecta, Dicondylia, and Neoptera. Alcohol-preserved and dried museum specimens will be used to assure the inclusion of the most basal lineages possible, thereby yielding a more robust data set. This approach, combining multiple loci, phylogenetically based sampling and extensive morphological analysis, ensures that this work will increase our understanding of the evolution and systematics of these, the oldest hexapod lineages.